theisen



(No Model.) 2 Sheets-Sheet 1. E THEISEN EVAPORATING APPARATUS.

Patented Feb. 24,1891.

(No Model.) 2 Sheets-Sheet 2.

E. THEISEN. EVAPORATING APPARATUS.

No. 447,210. Patented Feb. 24,1891.

UNITED STATES PATENT OFFICE.

EDUARD THEISEN, OF SlNZIG, GERMANY.

EVAPO RATING APPARATUS.

SPECIFICATION forming part of Letters Patent No. 447,210, dated February 24, 1891.

Application filed May 14, 1890. Serial No. 351,768. (No model.) Patented in Germany March 15, 1889, No. 51,010, and in v England June 18,1889, No. 10,048.

T0 at whom itmay concern:

Be it known that I, EDUARDTHEISEN, a citizen of the United States, residing at Sinzig-on-the-Rhine, in the German Empire, have invented new and useful Improvements in Evaporating or Drying Apparatus, (for which I have obtained a patent in Germany, dated March 15, 1889, No. 51,010, and in England, dated June 18, 1889, No. 10,048,) of which the following is a specification.

Figure 1 is a longitudinal section of drying apparatus illustrating my improvements. Fig. 2 is a vertical cross-section of the appatus shown in Fig. 1. Fig. 3 is a sectional detail view of concentric cylinders, some of which are formed with double walls. Fig. 4 is a longitudinal section of a modified form of drying apparatus. Figs. 5 and 5 are sootional views of other modifications. Fig. 6 is a cross-section of the construction shown in Fig. 5. Fig. 7 is a cross-section of another modification. Fig. Sis a longitudinal section. Fig. 9 is across-section of another modification. Fig. 10 is a longitudinal section of a form of apparatus in which the annular spaces are all open to the passage of hot air.

My invention has for its object a revolving drying or evaporating apparatus in which the material to be dried or evaporated is caused to pass through the longest possibledistance in the smallest possible space and with the greatest amount of motion given thereto, whereby the most advantageous utilization of the heat employed is etfected. The apparatus is in addition capable of treatinglarge masses of the material to be dried or evaporated. It

' is of inexpensive construction and has beyond the rotation of the apparatus no movable parts for stirring the material and requires but little driving power, because its parts are mainly balanced, as is also the charge of material passing through it.

The drying or evaporating medium mainly consists of hot air supplied from any suitable source, which is either made to flow in the same direction as or in the contrary direction to the material to be treated, motion being imparted thereto either by ablowing-fan, exhaust, or chimney-draft. If required, the apparatus may be made with steam-heated hollow sides to afford additional heat for drying.

Fig. 1 of the accompanying drawings shows a longitudinal section, and Fig. 2 a cross-section, of one construction of the above-described drying apparatus.

a is an external revolving cylinder, the hollow axis of which rests upon rollers cc, which have rotary motion imparted to them by suitable toothed gearing, thereby imparting rotary motion to the cylinder. Instead of a hollow axis may be used a solid axis running in fixed bearings. iNithin the cylindera are any desired number of concentric cylinders 61 e f, extending alternately from opposite ends 1 compartments in which are projecting ribs,

to which any desired form and position may be imparted for the purpose of turning over the material passing through. These ribs are so arranged that even when the apparatus is standing still the material cannot collect at the lowest part of the cylinders a d e f.

The right-hand end surface of the apparatus, Fig. 1, is provided near the periphery with an annular opening, through which the escape-pipe 9 projects into the apparatus.

This pipe is supported within the apparatus by an annular disk h, which does not partake of the motion of the apparatus, but covers the annular orifice through which pass the holders i of the disk, which are fixed to the upright k or otherwise. At the opposite end a fixed tube Z is fitted against the central opening of the revolving cylinder, which communicates with the hot-air pipe m and coldair pipe 41, and which carries the charginghopper 0, closed against the draft and supplied in any suitable manner. The inner end surface g at this end of the apparatus is of a less diameter than the cylinder, in order to allow of the discharge of the dried material through the chute p. All the supply and discharge pipes are provided with throttle valves for regulating the action.

If hot air be drawn in through pipe m by means of a fan and the apparatus be set in motion, the material will pass from the hopper 0 into the cylinder f, and will be caused by the rotary motion thereof to travel to the opposite end, where it falls into the cylinder e. Here the material is distributed into the several compartments, through which it travels back to the left-hand end again, where it passes into the cylinder (Z. Lastly, the material passes at the right-hand end into the cylinder a, from the left-hand end of which it is discharged into the chute 1). During the whole of this travel the revolution of the cylinders has, by the act-ion of the ribs, caused the material to be turned over and over, and in thus dropping through the air it is subjected in a very perfect manner to the evaporating action thereof. The quantity of hot air employed can be regulated by closing more or less the throttle-valve m and by admitting more or less cold air through 92., orby increasing or decreasing the action of the fan or chimney draft. As all the compartments or stirring-ribs are always equally charged, the load of the apparatus is always advantageously distributed, whereby the requisite power for driving the apparatus is greatly reduced.

For many substances the hot air will be sufficient for effecting the complete drying; but the action can be increased by constructing the cylinders with hollow sides, as at (Z and f, Fig. 3, and supplying steam to these from a central pipe for heating the same, the water of condensation being discharged by another central pipe into areceiving-ohamber. This arrangement is more particularly applicable when the material to be acted upon cannot be subjected to the direct contact of hot air, in which case either cold or warm air may be passed through, or the annular spaces may be subject to partial vacuum by a fan or pump.

In many cases, particularly when the current of the gases travels in the same direction as the material, the forward motion of the latter will be sufficiently effected if the revolving casings are made cylindrical. In other cases, such as where the current of the gases travels in the contrary direction to the material, the cylinders may be made somewhat conical, enlarging toward the delivery end, so as to accelerate the movement of the material. In the arrangement shown in longitudinal section at Fig. 4: the discharge-flue r for the gases is arranged centrally at the opposite end to the admission-flue, for which purpose an end surface s is provided,so that the currents of hot air with the evaporated constituents has first to travel from the central tube through all the other compartments before issuing at the outermost point into the space behind s, leading to the flue r.

In order to cause the current of hot air to flow in the contrary direction to the travel of the material, the apparatus may be arranged as shown in the section at Fig. 5, where the material is fed through the hollow axis either with or without the aid of a feeding-worm, as

shown, and being deflected by the end plate tis led to the outermost cylinder a, which, after carryingit round, delivers it at the other end into the next cylinder, and so on until it escapes through the right-hand end of the central cylinder, through whichthe hot air enters. The arrows 00 indicate the passage of the material and those y the passage of the hot air. In the arrangement at Fig. 1 the hot air and the material could also be made to travel in contrary directions by causing the hot-air current to enter through g and to escape through Z, while the material is introduced at 0 and discharged at 1).

Instead of arranging a number of cylinders concentrically, they may also be arranged parallel to each other, as shown in longitudinal section at Fig. 5 and in cross-section at Fig. (3.

The cylindrical or conical tubes are fitted into holes formed in end plates to of the outer shell a, the inclosed space within which surrounding the tubes may be supplied with steam for giving additional heat.

The passage of the material is as above described with reference to this figure, the material being supplied to the outermost tubes and, on issuing at the right-hand end, being directed by a ring shaped guide-plate r to the inner circle of tubes, from which it passes into the central tube f. These tubes may also have projecting stirring-ribs, as shown, in order to continuously raise and let fall the material passing through them. A

still more favorable stirring action will be obtained if the tubes, in addition to their rotation with the casing, have each an independentrotary motion imparted to them round their own axes, for which purpose the arrangem t shown in part longitudinal section at 1g. 5" may be employed. For this purpose the tubes are loose in the holes of the end plates to, and they are provided with central axes 2 z, fixed thereto, having their ends mounted in bearings in the end plates of the casing. Beyond the one end plate the axes are provided with toothed wheels 10, while to the upright 76 of the framing is fixeda toothed ring 10', with inner and outer teeth, with the outer teeth of which the wheels to of the outer ring of tubes gear, while the wheels to of the inner ringtof tubes gear. with the inner teeth. On rotating the outer cylinder and central tube by any suitable driving-gear the tubes, in addition to their rotation with the casing, will have a rotary motion round their own axes imparted to them by their toothed gearing, thus producing a very effectual stirring of the material, so as to present all particles thereof to the action of the hot-air currents.

Fig.7 shows a cross-section of modifications in the forms of the cylinders, the upper part showing a polygonal form, while the lower half shows a cylindrical form with a number of tubes.

hen drying materials holding a large quantity of moisture, it is advisable to carry IIO about by the stirring-ribs.

off the hot air charged with moisture at the end of each tube or cylinder. For this purpose the construction shown in longitudinal section at Fig. 8 and in cross-section at Fig. 9 can be employed. The tapering cylinders a Z) (Z c f are in this case arranged concentrically within each other and are carried on rollers c, as in Fig. 1. The spaces between I) and d and between 6 and fare closed at the left-hand end, while the cylinders a, cl, and f have conical extensions at the left-hand end which meet the fixed tube 1, with which the hot-air tube m and the cold-air tube 0?. communicate. In the tubes Z are two concen trically-fixed tubes 1' 1 so as to form three concentric channels for the hot air, of which the central one communicates with the tube f, the middle one with the space between 6 and d, and the outer one with the space between b and a, the entrance of the hot air into these several concentric passages being regulated by suitable valvular appliances 00 y 2'. These regulating-valves may also be arranged at the right-hand end of the cylinders instead of as shown.

The filling-hopper 0 for the material opens into Z so that the wet material first passes into the several compartments of the central tubef, while at the same time the hot air enters these compartments through Z taking up moisture from the material as this is moved At the end of f the hot air charged with moisture is drawn off byan exhaust-fan or chimney-flue through the pipe Z while the material passes from the end off into the cylinder e, in which it is 0011- veyed back/to the other end again, the space within this cylinder being without partitions or stirring-ribs in. order to accelerate the transit; but it may be formed as a conveyingpasses th ough spouts 1) into cylinder a, which It will be readily understood that the course of the material can be increased by the addition of further cylinders operating in the manner described, the hot-air passagesl being also last-described arrangement, in which the annular spaces are all open to the passage of the hot air, the material being fed into the central tube f and after traveling along the same falling into the tube 1), which is coned in the contrary direction, so as to cause the material to travel back to the left-hand end, where it falls into the outer cylinder a,which conveys it back tothe right-hand end again. The hot. air passes from the tube m simultaneously through all three cylinders a h f. a

In applyingthe above-described apparatus to the evaporating of liquids the liquid may either be made to flow in thin streams through the apparatus in the same manner as described with reference to the solid material to be dried, or the liquid may be charged into the bottom part of each concentric cylinder, which cylinders are formed with flanges at the ends to retain a certain quantity of the liquid, so that these cylinders in revolving carry up a thin film of the liquid on both surfaces, which is evaporated either by passing hot air or other gases through the cylinder, or by forming the cylinders with hollow double walls and heating them with steam, or byboth combined.

Having thus described the nature of my invention and the best means I know of carrying the same into practical effect, I claim In a rotating drying or evaporating apparatus, the combination of a series of concentric cylinders a b d e f, divided into compartments, passages ll Z for the supply of hot air to the cylinders a, d, and f, a flue Z for drawing off the hot air, and a hopper 0, supplying" ICC the central tube f with the wet material to be dried, from which tube the material-is made to pass successively through the cylinders e, d, b, and a, while being subjected to the currents of hot air passing through the cylinders a. d f, substantially as described.

In testimony whereof I have signed my name to this specification, in-the presence of two subscribing witnesses, this 14th day of April, A. D. 1890..

EDUARD TI-IEISEN.

Witnesses:

CHAS. D. ABEL,- J NO. P. M. MILLARD.

IIO 

